Assessment of Anti-inflammatory and Antioxidant Compounds in Gastrointestinal Digests From Germinated Amaranth Protein Concentrate

OBJECTIVES: Amaranth (Amaranthus hypochondriacus) is an ancestral nutritional grain with relevant nutritional value. The aim of this study was to evaluate the release of peptides and phenolics with antioxidant (AOX) and anti-inflammatory potential by simulated gastrointestinal digestion and absorption from a germinated amaranth protein concentrate (GAPC). METHODS: The in vitro simulated protein digestion of GAPC was achieved by enzymatic hydrolysis with pepsin (90 min) followed by pancreatin (60 min). After digestion of GAPC, two digests were attained: the absorbable (GAPC-out) and non-absorbable (GAPC-in), both were further fractioned to F1(>10 kDa) and F2(< 10 kDa) by ultrafiltration. The anti-inflammatory potential was determinate as percentage of nitric oxide (NO) inhibition in lipopolysaccharide-induced in RAW 264.7 macrophages and the AOX potential was evaluated using the oxygen radical absorption capacity (ORAC) method. The peptide and phenolics digests fractions were analyzed by high-performance liquid chromatography-mass spectrometry. RESULTS: The amaranth peptides from GAPC-in showed higher (p > 0.05) anti-inflammatory potential compared to GAPC-out. The NO inhibition percentages ranged from 42 to 87 by the assayed doses (0.25–1 mg/mL). Also, the F1 fraction presented higher NO inhibition percentages (p > 0.05) than F2 fraction from GAPC-in. Likewise, the phenolics in the GAPC-in digest showed better anti-inflammatory potential at 0.25–0.5 mg/mL doses (p > 0.05) than GAPC-out digest. Besides, the GAPC digestion increased 2.7-fold AOX (p > 0.05) compared to undigested GAPC. The GAPC-out digest showed higher AOX potential than GAPC-in digest. Moreover, in GAPC digests 18 peptides sequences were identified with potential health effect, whereas methyl gallate and syringic acid were the main phenolic presented in both digests. CONCLUSIONS: Finally, this study highlighted the potential of the germinated amaranth protein concentrate as antioxidant and anti-inflammatory functional ingredient to the prevention of inflammatory intestinal diseases. FUNDING SOURCES: Conacyt and Profapi.